The invention relates to a viscera retainer for use in surgery.
Retraction of organs is necessary in surgery when the operative field would otherwise be obscured by the position of the organs. This happens for example in removal of the gall bladder when the liver must be retracted to allow the bladder to be identified, mobilised and removed or in surgery in the pelvic area when the small and large intenstines must be retracted superiorly to permit access to the pelvic floor. Retraction can be achieved using surgical devices such as rigid retractors, soft surgical swabs, sponges or laparotomy packs.
Rigid retractors are usually flat metal or plastic devices that come in many shapes depending on the organ to be retracted. They are usually of a rounded, smooth construction in an attempt to be smooth against the wound edge or organ being retracted. A surgical department would have to have many of these different retractors for use in the different surgical procedures that were carried out in the hospital. These devices would usually be sterilisable and reusable. Rigid retractors are held in position either manually or by fixation to an external frame.
Swabs, sponges and laparotomy packs are gauze or other textile material folded several times into a square pack that may be rolled up or otherwise squashed into position in the abdomen to compress and displace internal organs away from the operative field. They are generally inconvenient to use.
EP-A-0267640 describes a form retainable unit comprising an airtight outer envelope, layers of flexible fibre material in the envelope and spheres between the layers of fiber material. On evacuation of the envelope the spheres become fixed in place and hold the envelope in a deformed holding configuration.
This form retainable unit works well in practice, however there are problems in manufacturing the required structure. Consequently, the costs of the manufactured unit are relatively high.
This invention is therefore directed towards providing an improved form retainable unit which will overcome at least some of these difficulties.
According to the invention there is provided a viscera retainer for use in surgery comprising an outer envelope of pliable material, the envelope having an evacuation port, and at least two sheets of material arranged in face to face relation in the envelope, the retainer having a malleable forming configuration in which the sheets are relatively free to slide over one another in manipulating the retainer to a desired shape, and a form retained configuration in which the sheets are restrained from sliding relative to one another on evacuation of the envelope to retain the viscera displaced from an internal body area to be accessed for surgery.
In one embodiment of the invention the sheets are of the same material. In this case, preferably the sheets are of an inelastic material.
In another embodiment of the invention the sheets are of different materials. In this case one of the sheets is of less elastic material than the other sheet.
In a preferred embodiment the sheet of elastic material is of a deformable open-cell structure.
Preferably the sheet of elastic material is of a foam material. The foam may be a polyurethane foam.
Preferably the sheet of inelastic material is of closed cell construction. The sheet of inelastic material may be of polystyrene.
In one case the unit includes at least three sheets of material in the envelope.
In one case a pair of sheets of less elastic material sandwich a sheet of elastic material therebetween.
In another case a pair of sheets of elastic material sandwich a sheet of less elastic material therebetween.
In one embodiment of the invention the retainer includes mounting means for mounting the retainer in or adjacent an incision.
Preferably the mounting means comprises a mounting ring to which the retainer is attached.
In a preferred embodiment the mounting means has engagement means for engaging with a surgical device. In one case the surgical device is a wound retractor.